The present invention relates to a reclining angle adjustment device for a reclining seat for cars, airplanes and so forth for adjusting the inclination of the seat back, more particularly, to a reclining angle adjustment device for a reclining seat which includes a pair of locking mechanisms comprising racks and pawl members, each pair of rack and pawl members being provided at either side of the seat and controlled to be engaged with and disengaged with each other by operation of a single handle.
In a reclining angle adjustment device including locking mechanisms provided at either side of a seat (i,e, an inner side and outer side of a seat), both locking mechanisms are designed to be operated, locked and unlocked almost simultaneously. Thus, in the art, a pair of release arms provided on locking mechanisms at either side of the seat are connected to each other by a connecting pipe thereby locking and unlocking the locking mechanisms by way of rotating a release arm which is provided at the outer side of the seat.
However, in the above fabrication, some disadvantages will appear where a gap exists between the outer locking mechanism and the inner locking mechanism with regard to their locking positions as illustrated hereinafter. That is, in this construction, there is no degree of freedom regarding to mutual movements between outer and inner locking mechanisms since both of them are connected with a connecting pipe as an integral body. Accordingly, when one of release arm reaches a locking position, the outer release arm may fall into an unlocking position since the latter cannot reach a locking position because of the existence of a gap between outer and inner locking mechanisms. Actually, the amount of movement, which is a distance between the stopping position of a release arm in the half-locked position and the locked position thereof to be reached, is difficult to keep zero since there exists inconsistences in parts thereof and constructions. Accordingly, when the types of devices belonging to the prior art are provided on a coach and so forth, either one of the locking mechanisms will fall into a half-locked position. Thus, the seat back becomes unstable and inconvenient for a passenger to sit thereon.